Normally, a jack is a weight-lifting tool being used widely for many purposes; especially, it is a indispensable tool for use in mechanical repair and assembling operations. A small type of jack not only is used in a specific working site, but it is also widely used in routine car maintenance work or in emergency repair work because of its portable nature; therefore, almost every car is provided with a jack. A small type of jack is capable of lifting 2,000 lbs to 4,000 lbs, and its weight is only from several lbs to several tens of lbs. The manufacturer usually packs such type of jack in a cardboard box having a given size; such cardboard box is merelyused for packing that kind of jack without being used for other purposes.